This invention relates to an apparatus and method for automatic stimulation of breathing mammals in response to blood gas analysis and more in particular to detection of apnea conditions.
At the present time, transcutaneous, membranous instruments are available for measuring a patient's oxygen and carbon dioxide status non-invasively and continuously by measuring the oxygen and the carbon dioxide concentration in the skin tissue of the patient. Also peripheral nerve stimulators are available. Also available are pulse oximeters to reliably measure hemoglobin saturation within oxygen by finger or earlobe sensors. In addition, external tidal capnographs are readily available to measure exhaled lung carbon dioxide as an indirect but accurate reflection of blood carbon dioxide. However, there is not available in the market an integrated apparatus which is capable of therapeutically stimulating a patient automatically in response to information supplied from an oxygen or CO.sub.2 measuring instruments so as to stimulate a patient to breathe more effectively when there is evidence that the patient's blood CO.sub.2 level is high or O.sub.2 is low compared to normal levels. There is therefore a need for an apparatus and method which can be used for reliably providing automatic stimulation of mammals in response to hypoxemic or hypercapnic conditions preceding true apnea by sensing the blood oxygen saturation level and/or CO.sub.2 level in the blood of the patient.